Friction-gear.



.` of the emmene. Jamison, or oHIcaGo, .-iLLINoIs, AssIGNon ro WILLIAM H. mman, or

I cnam', New Yoan.

EQRICTION-GEAB.

Togli whmt mag/"concern Be it known that l, GEORGE A. JOHNSON, a citizen of the United States, residin at Chicago, in the `cotinty .of Cookand tate of Illinois, have invented a certain newand -useful Improvement in Friction-Gears, of

which the following is a full, clear, concise, and exactl description, reference beingv had to the accompanying drawings, forming a partof this specification. l

This invention relates to improvements in friction gears.

One object of the invention is to provide a friction gear employing a friction shell having coperating friction shoes and wedge means, and a spring .for directly resisting movement of the shell as contra-distinguished from the usual arrangement wherein the spring directly resists the movement of the shoes. Another object of the invention is to provide a friction gear for railway draft rig-l ings so'arranged that a substantially uniorm or constant frictional resistance is provided durin the compressive action ofthe gear which rictional resistance is employed 1n tandem with a' spring resistance.;

The invention furthermore consists in the improvements in the parts and devices and in the novel` combina-tions of the parts and devices herein shown, described andclaimed.

1n the drawing forminga part of this specication, Figure l is a longitudinal section of a draft rigging showing my improvements in connection therewith, some parts being shown in elevation. Figs. 2 and 3 are vertical, transverse sectional views of the structure illustrated in Fig. 1. and taken on the lines 2-2 and 3-3 there-` of, respectively. And Fig. 4 is a detail perspective of the set of wedging elements employed in the gear.

in said drawing, 10-10 denote channel.

shaped center or draft sills of a railway car underframe to which are secured the usual rear stops 11 and front stops l.. The draw har 13 is operatively connected with 'the gear, hereinafter described., by means of a yoire '14:'. The parts are supported in proper position lov means of a saddle p ate l5 e .l i u ahiy holted to the danger; ci' the siii shown,

Specification of Letters Patent.- Application le' December 26, 1916. Serial No.

.comprises a ,ing an intermediate cylindrical .the parts,

.the

Patented Apr. 29, i919. 138,796.

preferably cylindrical friction shell 16 at the forward end of the gear, a series of circularly arranged friction shoes 17 mounted within the shell, a series of Wedges'lS mounted within the friction shoes, the shoes and wedges having cooperating wedge faces 19,- a rear follower 2O having a forwardly extended post 21, the latter havportion 22 anda forward cylindrical port1on`23 of lesser diameter than the portion 22. Surrounding the post 21 are the two coils 211 and.; 25 of the spring of'the gear, said coils bearing at their rear ends against the follower20 and at their forward ends against an inturned ange 26 formed on Athe rear end of the shell 16; A shoulder 27 is formed on the post 21 at the, rear end of said intervmedlate portion 22 Aand `against which bears the rear end of a light spring 28, the for- Wardend of said spring 28 bearing against the rear faces of the wedges 18 andnormallyv 4holding the latter slightly spaced from the shoulder 29 formed atthe junction between the cylindrical portions 22 and 23. The extreme forward end of the post is preferably threaded as indicated at 30 to receive a washer 31, which, in normal position of engages the' forward faces of the friction shoes 17. In said normal position, the rear faces of the wedges y18 also preferably engage the iange v26 formed on the rear end of the shell 16. A front follower 32'is also employed which is interposed between the butt of the draw bar'and the front end of the shell 16.

The spring 28 is employed merely for the purpose of maintaining the wedges and friction shoes and shell in proper en agement, that is, to prevent loosencss othe parts and the distance shown in the drawing between the shoulder 29 and the rear face of the wedge 18 is exaggerated to more clcariy illustrate this feature. In actual practice, said distance 'will 'ne very slight inasmuch there is practically no reiative nieveinent between the wedges 18 and the shoes l? flut."- ing the actuation of the in operation, upon inward movement draw har friction shell 1G thus or the near. .if-ini:

n'iil be ftit? Whatever clearance is provided between the Wedges 18 and said shoulder 29 will be talgen up during the initial portion of the action and thereafter a substantially constant or uniform frictional resistance will be maintaine'cllfbetween the friction shoes 17 and the shell 16, the main spring of the ear 4(coils 2i and 25) being entirely indepen ent of the v frictional action thus produced. Upon rev Will' ynim/*al of the pressure, the main spring of ,features ofthe invention is to so arrange the Wedges and friction shoes that the main spring of the gear does not act thereagainsty and to maintain a substantially constant frictional resistance. The spring 28 will not adect substantially the frictional resistance since thesaine is inerely. employed to preyent looseiiess of the parts, as heretofore described. ln this connection, it will be understood that there will be substantially no frici vtional resistance between the Wedges and the section 23 of the post and Whatever retiti ' sistance may possibly be produced between these elements can be considered as negligible since it occurs during an extremely short portionof the initial action of the gear. The Washer 31 isprovided to insuremain- "taining the friction shoes and Wedges inl` proper relation, in cooperation lwith the spring` 28.

Although l have herein shown and .de-

scribed what l now consider the preferred embodiment of the invention, the saine is merely illustrative and l contemplate all changes and modifications that come Within the scope ofthe'claims appended hereto.

l claini:

l. ln a friction gear, the combination With a set of friction members capable of relan tive movement and having a substantially uniform frictioiial resistance to said movenient during the compressive operation of the gear, of spring means fio-acting with one of said friction members for restoring the parts to normal condition after said action, said frictional resistance being obtained in dependently of said spring means.

2. ln a friction gear, the combination with a substantially constant resistance friction mechanism, of a spring resistance acting cumulatively with the friction mechanism during the entire operation of the gear, the spring' resistance co-actino directly with one of the members of the ,friction mechanism incinte without affecting thev degree of frictional resistance.

3. ln a friction gear, the combination with a substantially uniform resistance friction mechanism, of a spring, theresistance of the latter being added to that of the friction mechanism during the compressive action of thegear, said spring acting-to restore the friction mechanism to normal conditionduring release.

l. ln a friction gear, the combination with a friction mechanism including a friction shell, friction shoes and Wedge associated therewith, of va spring in axial alinement with .the friction mechanism and means, upon actuation of the friction mechanism, for compressing the spring in a direction to eiect a relative separation 'between said shoes and the end of the spring adjacent said shoes. n

5. ln a friction gear the combination with a friction cylinder, of a follower, a spring interposed between and Vresisting relative movement between said-follower and shell,

and a friction piston Within the cylinder co operable with the latter, all parts of said` piston being maintained at a substantially relatively fixed distance with respect to said follower at all times.

6. ln a friction gear, the combination with a friction shell, of a follower, a post extending from said follower within said shell,

Wedging means surrounding said post, a plurality o friction shoes mounted .Within said shell -and surrounding said means, the Wedging means and shoes being substantial y fixed `with respect to said post, and a spring interposed. between said follower and shell.

7. ln a friction gear, the combination with a friction shell, of a plurality of friction shoes mounted Within said shell and coperable therewith, a plurality of Wedge nele ments mounted Within said shoes, a follower,

a spring interposed between said follower, and shell, and means interposed between said wedge elements and the follower for maintaining a substantially fixed distance between said Wedge elements and said follower.

8. l'n a friction gear, the combination with a follower having a post extending theren from, of a series of Wedge elements mounted on said post, a shoulder formed on said post, a light spring extending between said shoulder and .said Wedge elements, the Wedge elements having a limited movement with respect to said post, a plurality of friction shoes disposed around said wedge elements, a friction shell Within which said slices are mounted, and a spring interposed between said follower and said shell.

' 9. ln a friction gear, the combination with a friction shell, of a series of friction'slioes mounted Within -the shell, a plurality of Wedge elements copcrable *with said shoes ilu" and disposed therewithin, a, follower having a post extending through seid Wedge elements and on Which the lat-ter are supported, a. lig-ht vspring for maintaining the Wedge 5 elements and friction. shoes `in proper engagement. with the shell, and a spring interposed between said shell and said folio-wer GEORGE A. JOHNSON. 

